In the rapidly evolving world of mobile devices, communication standards are constantly changing, and new features are constantly developed for devices, even after they have been sold to users. For example, mobile electronics developers may continuously provide software and/or firmware updates to electronic devices that add additional functionality to the device. Updates may also be provided in order to fix existing bugs in the device, or to ensure that the device conforms to the latest standards. In addition, mobile devices may be updated with security enhancements that prevent the devices from being compromised. Any many other examples of possible software and/or firmware updates are possible as well.
Typically, the standard used to notify mobile devices of the presence of software and/or firmware updates is the Open Mobile Alliance-Device Management (OMA-DM) standard. Under the OMA-DM standard, if an update is available for a mobile device, an OMA-DM server notifies the mobile device that an update is available by sending a Short Message Service (SMS) message to the mobile device. Alternatively, the mobile device may periodically check with the OMA-DM server for updates. Upon receipt of the SMS message, the mobile device may obtain the update by initiating an Internet Protocol (IP) session with the OMA-DM server.
Many wireless communication devices communicate using the Mobile-IP protocol. Mobile-IP capable devices remain reachable at the same IP address while moving from one network to another. With Mobile-IP, a mobile device obtains and uses a Mobile-IP address referred to as a home address (HoA). Packets to the mobile device are then routed through a Mobile-IP home agent located on the mobile device's home network, and then forwarded to the mobile device using a care-of address, which may be a temporary IP address used by a mobile node while it is located on a foreign network. A more complete explanation of Mobile-IP may be found in C. Perkins et al., “IP Mobility Support for IPv4,” Request for Comments 3344, August 2002, the contents of which are incorporated herein by reference, and D. Johnson et al., “Mobility Support in IPv6,” Request for Comments 3775, June 2004, the contents of which are also incorporated herein by reference.
In addition, Mobile-IP uses a general “extension” structure that allows optional information to be appended in Mobile-IP control messages. For example, a mobile device may append its network access identifier (NAI) in a Mobile-IP registration request to assist in the authentication process.